The Guardian’s expansion into the United States is on track, editor-in-chief Alan Rusbridger (see disclosure) said at the paidContent Live conference Wednesday. Rusbridger said that the Guardian’s global audience is about 40 million readers, according to comScore data, with one-third of them in the U.S., one-third in the U.K. and one-third in the rest of the world.

“It wasn’t us waking up one morning saying, ‘let’s impose The Guardian on these Americans,'” Rusbridger told GigaOM/paidContent senior writer Mathew Ingram. The Guardian’s U.S. traffic grew at around 37 percent last year, Rusbridger noted, while the site’s traffic as a whole grew by 25 percent. But before the decision to expand to the U.S., “we spent no money marketing to America at all.”

Now the monetization has begun, but Rusbridger says that probably won’t include a paywall, though the paper is “open-minded” on the idea. “I think it’s great that people are trying,” he said. “It would be even greater if people would share all the data so we could tell whether they’re working or not…it would be a big statement, in the U.K., to go and charge for what the BBC is giving away for free.”